The structure of spray-dried detergent powders

Drying kinetics and energy efficiency of soot ash of smelting silicon manganese alloys under microwave heating

When smelting silicon manganese alloy in an industrial electric furnace, it will produce smoke and dust waste gas, which can be utilized again back to the furnace and improve the utilization rate of raw materials after a particular trapping device and collection treatment. However, at higher moisture levels, they are prone to explode. Effects of various initial masses, initial moisture contents, and microwave output powers on the soot ash of smelting silicon manganese alloy were studies. The findings indicate that the microwave drying rate increases with all three variables. The time for complete microwave drying is directly proportional to the sample's initial moisture content and the sample's initial mass, and the time for complete microwave drying is inversely proportional to the microwave output power. The results demonstrate that the Modified Page model can accurately describe the microwave drying process. The experimental data were fitted experimentally by drying kinetic models. Microscopic characterization of soot ash from refining silico‑manganese alloys before and after drying was carried out using FTIR and SEM. Through FTIR characterization, the peak value of the -OH absorption peak decreases upon drying, and SEM results in no agglomeration caused by microwave drying and better dispersion of the soot ash of the dried smelted silica‑manganese alloys, all of which proved that microwaves could effectively remove water. It was discovered that the diffusion coefficient increased gradually with increasing power when it was computed using Fick's second law. The diffusion coefficient increases and then decreases as the moisture content increases. The diffusion coefficient decreases as the initial mass increases. Activation energy of microwave drying of soot ash from the refining of silicomanganese alloys was calculated to be -1.4467 W/g. Its purpose is to offer a detailed guide for the industrial drying of soot ash from silicomanganese alloy refinement using microwave drying technology.

Multilayer microparticles for programmed sequential release of phenolic compounds from Eugenia stipitata: Stability and bioavailability

A co-delivery system based on multilayer microparticles was developed and characterized for the sequential release of phenolic compounds (PCs) using different encapsulation processes (spray drying: SD and drying-chilling spray: SDC) and wall materials to improve the stability and bioavailability of PCs. Samples were characterized in terms of process yield (PY%), phenolic retention efficiency (PRE%), chemical structure and crystallinity (NMR, FTIR, DXR), thermal stability (DSC and FT-IR), anti-radical capacity (ORAC and ABTS) and in vitro digestion. PRE% of samples by SD were higher (p < 0.05) than SDC due to the formation of PCs from CRF (cará-roxo flour). NMR, FTIR, DXR confirmed the presence of key components and interactions for the formation of the advanced co-delivery system. The SDC particles showed crystalline regions by XRD and were stable at ∼47 °C. All samples showed good release of PC in the intestinal phase, and antiradical capacity that reached 23.66 µmol TE g-1.

Relationship between the Young's Moduli of Whole Microcapsules and Their Shell Material Established by Micromanipulation Measurements Based on Diametric Compression between Two Parallel Surfaces and Numerical Modelling

Micromanipulation is a powerful technique to measure the mechanical properties of microparticles including microcapsules. For microparticles with a homogenous structure, their apparent Young's modulus can be determined from the force versus displacement data fitted by the classical Hertz model. Microcapsules can consist of a liquid core surrounded by a solid shell. Two Young's modulus values can be defined, i.e., the one is that determined using the Hertz model and another is the intrinsic Young's modulus of the shell material, which can be calculated from finite element analysis (FEA). In this study, the two Young's modulus values of microplastic-free plant-based microcapsules with a core of perfume oil (hexyl salicylate) were calculated using the aforementioned approaches. The apparent Young's modulus value of the whole microcapsules determined by the classical Hertz model was found to be EA = 0.095 ± 0.014 GPa by treating each individual microcapsule as a homogeneous solid spherical particle. The previously obtained simulation results from FEA were utilised to fit the micromanipulation data of individual core-shell microcapsules, enabling to determine their unique shell thickness to radius ratio (h/r)FEA = 0.132 ± 0.009 and the intrinsic Young's modulus of their shell (EFEA = 1.02 ± 0.13 GPa). Moreover, a novel theoretical relationship between the two Young's modulus values has been derived. It is found that the ratio of the two Young's module values (EA/EFEA) is only a function on the ratio of the shell thickness to radius (h/r) of the individual microcapsule, which can be fitted by a third-degree polynomial function of h/r. Such relationship has proven applicable to a broad spectrum of microcapsules (i.e., non-synthetic, synthetic, and double coated shells) regardless of their shell chemistry.

Aqueous Phase Behavior of a NaLAS-Polycarboxylate Polymer System

Linear alkylbenzene sulfonate (NaLAS) surfactant is often combined with polycarboxylate polymers in detergent formulations. However, the behavior of these aqueous surfactant-polymer systems in the absence of an added electrolyte is unreported. This work investigates the behavior of such systems using polarized light microscopy, small-angle X-ray scattering (SAXS), centrifugation, and ²H NMR techniques. A phase diagram at 50 °C is reported for 0-50 wt % NaLAS concentrations and 0-10 wt % polycarboxylate concentrations. The NaLAS-water system is micellar at concentrations <35 wt %, and a 2-phase micellar-lamellar system is seen at higher NaLAS levels, consistent with that reported by previous studies. As polymers are added at low surfactant concentrations (∼10 to 20 wt % NaLAS), a second optically isotropic phase is formed; this is thought to be a polymer-rich phase. Further addition of polycarboxylate leads to the formation of a lamellar phase. At high surfactant concentrations (>20 wt % NaLAS), the addition of a polymer induces a second lamellar phase. These observed behaviors are thought to arise as a result of depletion flocculation and salting-out effects. The observed lamellar phases adopt colloidal multilamellar vesicle (MLV) structures, and the average MLV radii were estimated using ²H NMR by probing the diffusion and anisotropy of D₂O within the bilayers of the vesicles. The NMR results show that as the polymer concentration was increased from 0 to 10 wt %, an increase in the average multilamellar vesicle size from ∼200 to ∼500 nm was observed. This increase in the calculated average MLV radius likely results from depletion flocculation-induced MLV fusion.